import { defineStore } from 'pinia'

import { useOAuthStore } from 'src/stores/oauth.js'

import {
  getAnnouncements as adminGetAnnouncements,
  deleteAnnouncement,
  editAnnouncement,
  postAnnouncement,
} from 'src/services/api/admin.js'
import {
  dismissAnnouncement,
  getAnnouncements,
} from 'src/services/api/api.service.js'

const FETCH_ANNOUNCEMENT_INTERVAL_MS = 1000 * 60 * 5

export const useAnnouncementsStore = defineStore('announcements', {
  state: () => ({
    announcements: [],
    supportsAnnouncements: true,
    fetchAnnouncementsTimer: undefined,
  }),
  getters: {
    unreadAnnouncementCount() {
      if (!window.vuex.state.users.currentUser) {
        return 0
      }

      const unread = this.announcements.filter(
        (announcement) => !(announcement.inactive || announcement.read),
      )
      return unread.length
    },
  },
  actions: {
    fetchAnnouncements() {
      if (!this.supportsAnnouncements) {
        return Promise.resolve()
      }

      const currentUser = window.vuex.state.users.currentUser
      const isAdmin =
        currentUser &&
        currentUser.privileges.has('announcements_manage_announcements')

      const fetchAnnouncements = async () => {
        if (!isAdmin) {
          return getAnnouncements({
            credentials: useOAuthStore().token,
          })
        }

        const all = await adminGetAnnouncements({
          credentials: useOAuthStore().token,
        })
        const visible = await getAnnouncements({
          credentials: useOAuthStore().token,
        })
        const visibleObject = visible.reduce((a, c) => {
          a[c.id] = c
          return a
        }, {})
        const getWithinVisible = (announcement) =>
          visibleObject[announcement.id]

        all.forEach((announcement) => {
          const visibleAnnouncement = getWithinVisible(announcement)
          if (!visibleAnnouncement) {
            announcement.inactive = true
          } else {
            announcement.read = visibleAnnouncement.read
          }
        })

        return all
      }

      return fetchAnnouncements()
        .then((announcements) => {
          this.announcements = announcements
        })
        .catch((error) => {
          // If and only if backend does not support announcements, it would return 404.
          // In this case, silently ignores it.
          if (error && error.statusCode === 404) {
            this.supportsAnnouncements = false
          } else {
            throw error
          }
        })
    },
    markAnnouncementAsRead(id) {
      return dismissAnnouncement({
        id,
        credentials: useOAuthStore().token,
      }).then(() => {
        const index = this.announcements.findIndex((a) => a.id === id)

        if (index < 0) {
          return
        }

        this.announcements[index].read = true
      })
    },
    startFetchingAnnouncements() {
      if (this.fetchAnnouncementsTimer) {
        return
      }

      const interval = setInterval(
        () => this.fetchAnnouncements(),
        FETCH_ANNOUNCEMENT_INTERVAL_MS,
      )
      this.fetchAnnouncementsTimer = interval

      return this.fetchAnnouncements()
    },
    stopFetchingAnnouncements() {
      const interval = this.fetchAnnouncementsTimer
      this.fetchAnnouncementsTimer = undefined
      clearInterval(interval)
    },
    postAnnouncement({ content, startsAt, endsAt, allDay }) {
      return postAnnouncement({
        credentials: useOAuthStore().token,
        content,
        startsAt,
        endsAt,
        allDay,
      }).then(() => {
        return this.fetchAnnouncements()
      })
    },
    editAnnouncement({ id, content, startsAt, endsAt, allDay }) {
      return editAnnouncement({
        id,
        content,
        startsAt,
        endsAt,
        allDay,
        credentials: useOAuthStore().token,
      }).then(() => {
        return this.fetchAnnouncements()
      })
    },
    deleteAnnouncement(id) {
      return deleteAnnouncement({
        id,
        credentials: useOAuthStore().token,
      }).then(() => {
        return this.fetchAnnouncements()
      })
    },
  },
})